Centering device.



J. B. BLAW. GENTERIN G DEVICE- APPLICATION TILED JAN. 18, 1909.

i Patnted llaig 11; 1910 INVENTOR- I wi-i-m'asfsa the provision of improved stiffening means tween the flanges of Ys rars rarnncr ensues.

COLLAPSIBLE CORPORATION JACOB B. BLAW, OF PITTSBUBG, PENNSYLVANIAQASSIGNQB T0 BLAW STEEL CENTERING COMPANY, OF PITTSBURG, PENNSYLVANIA, A

OF NEW JERSEY.

CENTEBING DEVICE.

Specification of Letters Patent. j 'atgnted Jan, 11, 1910,

Application filed January 18, 1909. Serial No. 472,797.

high degree of rigidity is imparted by means of the stiffening plates F and G at the ends of the sections. By means of this arrange ment the shell is made sufficiently resistant to do away with the necessity of providing cross braces which are undesirable, as they obstruct the passage through the centering, and are objectionable for other reasons. 1t will be apparent that the invention is not limited to the use of stiffening plates of the shape illustrated in Figure 1, nor is it limited to the arrangement shown wherein the plates overlap thus making break joints, al though this is the preferred arrangement. It is also obvious that different forms of stiffening ribs other than the channels may be used if desired.

Having thus described my invention and To all whom it may concern:

Be it known that I, JACOB B. BLAW, a citizen of the United States, residing at Pittsbur'g, in the county of Allegheny and State l of Pennsylvania, have invented certain new and useful Improvements in Centering Devices, of which the following is a specification.

The invention relates to centering devices for use in the formation of concrete conduits and the like. It has for its principal obfect;

for the shell or lagging. One embodiment of the invention is illustrated in the accompanying drawing, wherein.

Figure 1 is a section on the line I-I of Figure 2 looking in the direction of the arrow, and

Figure 2 is a longitudinal section on a reillustrated its use, what 1 claim as new duced scale, taken on the line IL-II of and desire to secure by Letters Patent, is

the following:

1. A curved stiffening rib for centering comprising a pair of' flanged sections with their flanges in opposition, a succession of overlapping plates between the flanges, and means for securing the flanges to the plates.

2. The combination with a pair of curved centering sections end to end and provided at their meeting ends with flanged sections, of a succession of overlapping stiffening plates between the flanges, and means for securing the flanges to the plates.

3. The combination with a pair of curved centering sections end to end and provided at their meeting ends with a pair of flanged Figure 1.

Briefly stated, the centering comprises a plurality of sections which may be detachably secured together in series, end-to-end. Each of these sections consists of a metal shell or lagging which is prefe ably stiffened intermediate its ends by means of channel bars or other flanged ribs. The sections are also provided at their ends with flanged stiffening members adapted to be secured together, and other stiffening means are pro vided intermediate the stiffening members, i for giving additional strength to the sections when secured together in series.

My invention relates particularly tothe stiffening construction at the ends of the centering sections, which construction will he hereinafter described in detail.

Referring to the drawing, and particularly between the tlangesof' the pair of sections, and means for securing the flanges to the plates.

Figure 2, A, 15/6, are lagging sections ar- 4. The combination with a pair of cenranged cnd-to-end as indicated provided tering sections end to end and each pro- 61 The combination with a pair of curved centering sections end to end and provided at their meeting ends with flanged sections,

intermediate their ends with the circumferential stiffening channels D. The opposing ends of the sections are also provide with stiffening channels E. Inter-posed bethe channels E are two series of stiffening plates F, G, which series of plates are arranged with break joints. as indicated in Figure 1, the purpose being to provide a continuous stiffening rib of substantially uniform resistance. The flanges of the channels E are rigidly secured to the and to each other, by means The centering is thus plates F- and G of' the bolts H. readily made separable in sections, while a sections, of a succession of stiffening plates eeeeee 01" a succession of two series 01? plates makfor securing each plate to the flanges at a 10,

mg break joints with each other interposed plurality of points intermediate its ends. between the flanges, and means Qetacn- In testlmony whereof I have hereunto ably securing ehe piates and flanges together. slgned my name 111 the presence of the two FACOB B. BLAW.

| I I. A curved. stlffening rib fer centering suoscribed Witnesses. comprising pair of flanged sectiens with I e 1 VVitDQSSES:

f ARCHWORTH lE/EA TIN,

F. MARTIN.

their flanges in eyeoeition, two series 0i making break jomts Wlth each mile? wa ed beaween the fiumges, and; enemas 

